Cailiao Baohu (Sep 2023)
Effect of Sintering Temperature on the Microstructure and High Temperature Oxidation Resistance of Silicide Coating on Surface of NbW Alloy
Abstract
Silicide coatings are the most commonly used high-temperature protective coating for niobium alloy high-temperature structural components used in aerospace and aviation.In order to improve the performance of silicide coating and meet the increasingly stringent service conditions of niobium alloy high-temperature structural components， silicide coatings were prepared on the surface of NbW alloy by slurry fusion sintering method.By changing the sintering temperature of the coating (1 350，1 400，1 450，1 500 ℃)， the effect of sintering temperature on the microstructure and high-temperature oxidation resistance of the coating was studied.Results showed that the main components of the dense layer of the 4 kinds of sintering temperature coating were (Nb， X) Si2(X was Zr， Cr and Ti)， and the transition layer was stable Nb5Si3.The coating was oxidized at a high temperature of 1 600 ℃for 2 h，the oxidation reaction mainly occurred in the loose layer on the surface，and the elements such as Si， Zr， Ti， Cr were selectively oxidized.ZrO2 was dispersed in the SiO2 glass film as "oxide nails"，and the coating exhibited good high temperature oxidation resistance.The high temperature oxidation resistance of the coating at the sintering temperature of 1 350 ℃was the best.
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